The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingBrake master cylinder
Components
On-vehicle inspection
Check brake fluid level warning switch
Remove the reservoir filler cap and strainer.
Disconnect the brake fluid level warning switch
connector.
Measure the resistance of the switch.
Hint:
There is a float inside the reservoir. Its positio ...
Data list / active test
Read data list
Hint:
Using the intelligent tester's data list allows switch,
sensor, actuator and other item values to be read without
removing any parts. Reading the data list early in
troubleshooting is one way to save time.
Connect the intelligent tester (with can vim) to the
...
Short in can bus lines
Description
There may be a short circuit between the can bus lines when the resistance
between terminals 6 (canh)
and 14 (canl) of the dlc3 is below 54
.
Wiring diagram
Inspection procedure
Notice:
Turn the ignition switch off before measuring the resistances of the
main ...